THE GROUPS OF ANGIOSPERMS.' 
A. ENGLER. 
[IN the form of a supplement? to Parts II, III, and IV of Die Natir- 
liche Pflanzenfamilien, Dr. Engler has presented a comprehensive review of 
the taxonomic divisions of spermatophytes. In it he has made important 
alterations in the sequence and structure of the series as arranged and 
elimited in the original work. In the light of results obtained since the 
publication of the earlier parts of the Pflanzenfamilien, a rearrangement - 
been made of which the following abstract from the author’s “ Erlauterungen 
serves to give a general idea. Even the more important details have been 
rigidly omitted, and for a comprehensive grasp of the reasons for the changes 
the reader must be referred to the “key” which forms the skeleton of the 
supplement, and to the context.—Eps: ] 
The sequence of series and families is treated with special 
reference to the progressive steps which are manifested in floral 
structure, fruit and seed development, and differentiation of 
tissue. 
Certain difficulties present themselves in the practical carry- 
ing out of such a-scheme. It often occurs that within one 
circle of relationship a certain tribe has advanced in sone goed 
ticular direction, remaining latent in other directions, while the 
reverse may be true of other related tribes. In other cases it 1S 
doubtful whether certain lower stages are primitive, or whether 
they have arisen through reduction. Haat 
Eichler has recognized the so-called apetalous families 
dicotyledons as haplochlamydeous, or naked-blooming, inst" 
of abortive, and has placed them at. the beginning of oe 
dons. To these I have added Piperales, Proteales, Santalales, 
and Aristolochiales. 
* Abstract of translation prepared by Dr. Edwin B. Uline. einen, Unter 
*ENGLER, A.: Ubersicht iiber die —— eeig: Wilhelm Engel- 
reihen und Familien der Embryophyta siphonogama. ep 
mann. 1897 [may 
338 
